Question about injectors and turbos...

[sganc4life_4]

Well, If I were to get an evo3 16g turbo, are the stock injectors too small? What size should I go with for running 15-16psi? I know to get dsmlink and I know I would have to get a FMIC, but I dont know about injectors...thanks

[blk_srt]

If you plan on maxing out the turbo you will need 680s or 720s to be safe. 550s will get you to the 16psi mark though(I have some that I'm willing to sell)

[sganc4life_4]

I wanna stick with 16psi because Ill need something reliable after a rebuild, Ill dump money into my car once Im good and set with my career in a year or 2 , how much are you willing to sell them for?

[steviek]

for 16 psi I don't think you NEED to get a fmic I would say its always a good idea but not entirely necessary. I think 660's are good to max out that turbot but the extra room with bigger couldn't hurt (as long as you have link not safc). Does link show A/F ratios or do you need to get a gauge?
Can you add ur mods in your signature so we can see what your running
Oh yea and I beaat NFSMW the ending is really fun don't want to spoil it for ya

[blk_srt]

Originally Posted by sganc4life_4

I wanna stick with 16psi because Ill need something reliable after a rebuild, Ill dump money into my car once Im good and set with my career in a year or 2 , how much are you willing to sell them for?

Pm me with an offer, they are almost new rc's I believe but there isnt a sticker on them, I was going to use them but I diceded to go bigger.

[scottsee]

Why would you even bother buying an evo3 turbo with the intentions of not running higher then 16psi? Thats pointless.

You'll want 660's or higher with that turbo, and most defnitly want a FMIC.

[clipsekid99]

Originally Posted by scottsee

Why would you even bother buying an evo3 turbo with the intentions of not running higher then 16psi? Thats pointless.

You'll want 660's or higher with that turbo, and most defnitly want a FMIC.

So when I get my evo3, I will need to buy 660s? I don't really plan on going dsmlink, even though I should for best performance, but aren't the 660s hard to tune out on the safc2?

[Killa]

Originally Posted by steviek

for 16 psi I don't think you NEED to get a fmic I would say its always a good idea but not entirely necessary. I think 660's are good to max out that turbot but the extra room with bigger couldn't hurt (as long as you have link not safc). Does link show A/F ratios or do you need to get a gauge?
Can you add ur mods in your signature so we can see what your running
Oh yea and I beaat NFSMW the ending is really fun don't want to spoil it for ya

im about to race the lancer evo 8 guy.

[blk_srt]

It took me a week to beat that game

[steviek]

Haha Ricer I don't know if thats a good thing or a bad thing...
Anyways safc2 can go +-50% so ur still ok with 660's link can do 60% I think but I don't have it.
edit. I just realized you have safc2 so you know all that already I guess the difference is it just lies to ur ecu where link changes it (which is just dandy till u lose power)

[LouieAWDTSi]

I have a ported evo 3 gt which is fully ported compared the evo 3 MHI. I run 17 psi with 550's, safc, and few other goodies in my sig. No front mount yet, but my car defiantly gained more power. Its not so bad to only run 16 or 17 on an evo 16g. Just support it with the fuel stuff and youll be happy.

[kjewer1]

That maft thing will still completely bollix timing though, and since I can't live with that, I still have to recomend DSMlink.

660s require 32% adjustment for injector compensation, 450/660-1. That leaves 18%, 14% of which is required to get to 11:1, 9.5/14-1. Which then leaves only 4% for trim adjustment, or futher leaning out on race gas, which isn't much. Either way, I don't recomend using that much of the AFC's 50% range unless you have some way to lower base timing (1g, or 2g with 1g CAS). I've gone over some of the math in the past outlining how to figure out how much air you have to flow to make a particular adjustment factor give stock or at least reasonable timing curves. Without going through it now, I would guess that a 16g is not even capable of enough flow make 660s look stock as far as timing advance goes.

I've also never been much of a fan of the "80% rule." Probably just because I have run injectors at 100% and more for years on end with no noticeable or measureable side effects. In fact I just upgraded the EVO to 950s, just because I can, but it's run the last year at 102-103% IDCs on the stock 580s. Doesn't mean it's a good idea, but I have to ask myself what is worse, running an injector at 95% IDC which seems to have no real side effects, or running 28 degrees of ignition timing on pump gas, which does have known side effects This is a very tough topic to debate, since there are so many variables, most of which are in the mind/strategy/budget/risk tolerance/etc of the owner. My recomendation can even change slighty depending on the mood I'm in

To try to make my take on this short. If you are on an AFC or other ECU porking device, with no way to compensate for base timing (still a hack mod, since it makes changes across the whole rpm range, which is of course undesireable at idle for example) keep the injectors on the smaller side of what you can get away with. For example, 550s will support 40 lbs/min at 100% with all the usual variables accounted for. It takes a bit of work to get that from an EVO 16g on pump gas. On race gas they are good for ~42 lbs, and not many poeple will ever see over that. I get 43 on occasion, and at least one other person reported 44. But on race gas, you've got some fudge factor anyway. This will be acceptable to most poeple. To take it one step further, you would need to be flowing about 32 lbs/min at 6k rpm to keep the ECU over it's percieved 2.1 g/rev point, keeping WOT timing in control. Certainly attainable by the average guy, even at relatively low boost. Though it may take a little more than 16 psi, IIRC.

In contrast, 650s make much more sense. They can support 48 lbs/min, and with a maxed out evo3 at 43, you're looking at 89% IDC. Certainly reasonable, and at something like 35 lbs you're down at 73%. So even if your boost line falls off the WG and you completely max out the turbo, the ECU will know this, try to add fuel, and if you have enough pump, the capacity is there to save your motor. Certainly makes good sense to go this route.

But let's look at the other side of the coin now with 650s, with an AFC-like device, and no way to adjust for timing. Airflow is going to be hacked by about 46%, as described above (injector compensation and leaning to ~11:1 only, no other adjustment). You need to be flowing ~51 lbs/min at 6k rpm to stay over the 2.1 g/rev cutoff. Not going to happen So timing will be increased. To try to get an idea of how much, let's use the 35 lbs/min example again since it's not hard to reach that on pump gas. At 6k rpm the ECU is going to see 1.4 g/rev. WELL below the 2.1 rev range. Unfortunately I have no good way to calculate or look up what the target timing advance will be at that point, but it will be well into the 20s. No longer very safe or reliable IMO.

So this becomes a difficult decision between having plenty of fuel on hand to cover the unthinkable (but inevitable) but with excessive timing advance, or pushing your luck with less fuel capacity, but having safer timing advance. It's not an easy choice, but I have to lean to the smaller injector here, which is very unlike me. And this is the reason I always seem to push DSMlink so much. Eliminates the compromise, and is good not only for making the most power you can on your setup, but for increasing safety as well!

[speech]

You can also see that the more you know about this stuff, the harder it can be to make these choices. 99.9% of poeple have never even considered the numbers I went through above. And they may be pretty successful. But we really need to be fully informed. Even if it makes things a little more scary and a little tougher to decide, at least we know we are making educated decisions. So while all the jackasses say things like "Just get the 550s, so and so ran 9s on them!" I feel we should all take the time to make the right choice for the right reasons.

[/speech]

I could go on for hours about this, so I regret having to cut it so short. Hope this helps people out anyway.

[blk_srt]

Another great write up. So your saying that with a rewired 190 and 550s that will be enough for a s16g if the injectors are running at 100% IDC?

[kjewer1]

"enough for a 16g" is a subjective question. If you lose control of boost and max out the turbo, it may not be enough. For the average person with no crazy failures, it will be enough. I usually go on about how you should size all fuel system components to the max airflow the turbo is capable of, but with all this ECU fuckery it's a little more complicated But to reiterate, I have seen no problems running at 100% IDC, or close to it, but that's not to say I think it's an ideal situation either

The 190 rewired is juuust big enough to support an evo 16g. In the case of fuel pumps however, you can go bigger and not incur any real penalties. So it can make much more sense to go bigger. But of course, taking the next step to a 255 really does require an AFP in my humble opinion. In the max boost scenario above I think the 190 would fare better than the 550s, so it may be a worthwhile risk if the AFPR really isn't in the budget.

Again, so much of this is subjective and open to so many variables, it's hard to give straight answers. I know it sounds like I argue "yes" and "no" at the same time on this topic, but it should provide poeple with the necessary info to make the call. If everyone could run DSMlink, my suggestion would be 950s all day long, and the world would be much simpler...

[blk_srt]

I'm actually thinking about selling my afc and 550s and just getting dsm link(should have done it from the start)